The present disclosure relates to the field of patient monitoring. More specifically, the present disclosure relates to monitoring the functioning of an implantable device using surface ECG by receiving the surface ECG and producing an analysis of the monitored implantable device function.
Electrical impulses originating in the tissues of the heart cause the heart to cyclically contract. When, due to heart disease or tissue damage, the heart tissue fails to properly create and/or propagate these electrical impulses, an artificial electronic pacemaker may be implanted to provide the necessary stimulation. The design and implementation of an electronic device that is implanted into the body of a patient is a challenging task. The interior of the human body presents a hostile and dynamic environment in which the pacemaker is required to function. Challenges arise to proper pacemaker function both in terms of the constantly moving and changing environment in which the pacemaker must operate, as well as the body's own defensive mechanisms aimed to isolate and destroy any foreign objects.
Studies have found that pacemaker lead fractures can occur at a rate between 0.1% and 4.2% per patient-year. Additionally, atrial and right ventricle dislodgments, on average, occur at a rate of 2.2% per patient-year. Furthermore, left ventricle lead dislodgment, on average, occurs at a rate of 8% per patient-year.
There are three categories of the most common pacemaker complications. These categories include failure to sense, failure to capture, and inappropriate rate. A failure to sense complication is a pacing system malfunction in which the pacemaker fails to properly detect the electrical stimulation of the heart muscle tissue. A failure to capture complication is a pacing system malfunction in which the pacemaker fails to generate a pace pulse with sufficient power to stimulate the myocardium (heart tissue). Inappropriate rate is a pacing system malfunction in which the pacemaker generates the pacing pulses at either too low or too fast of a rate.
Since the pacing system works in conjunction with the heart's own biopotentials, the artificial electronic stimulation of the heart by the pacing system may be detected through the use of an electrocardiogram (ECG). An analysis of the electrical activity in the heart as shown by the ECG can be used to identify whether the pacemaker is properly functioning, or can be used to identify which of the above-referenced complications are being experienced by the pacing system.
While systems for detecting the existence of a pacing system complication or malfunction have been available, these systems have not taken this analysis any further. Therefore, often once a pacing system malfunction has been detected, complicated and time consuming techniques such as chest X-rays and RF communication with the pacemaker must be used to further distinguish the cause of the pacing system malfunction.